Optical energy, particularly laser energy, is commonly used for industrial purposes, for example, to cut or weld materials. Optical energy is also commonly used as a versatile tool in medicine to achieve desired outcomes in a tissue that is treated. For example, lasers and other forms of intense light have been used to treat common dermatological problems such as hypervascular lesions, pigmented lesions, acne scars, rosacea, and/or for hair removal. Forms of optical energy are also used for cosmetic purposes, to achieve a better cosmetic appearance by resurfacing the skin, by remodeling the different layers of skin to improve the appearance of wrinkled or aged skin, and/or by tightening the skin. Generally, skin resurfacing is understood to be the process by which the top layers of the skin are completely removed using chemicals, mechanical abrasion or optical energy in order to promote the development of new, more youthful looking skin and stimulate the generation and growth of new skin. In laser skin remodeling, laser energy penetrates into at least a portion of the deeper layers of the skin and is aimed at stimulating the generation of and/or altering the structure of extra-cellular matrix materials, such as collagen, that contribute to the youthful appearance of skin.
During dermatological tissue treatments utilizing optical energy, a beam of optical energy irradiates the surface of a patient's skin. Generally, optical energy based devices that are used for such treatments operate at wavelengths that are absorbed by one or more absorbing species naturally present in the skin, such as, for example, melanin, hemoglobin, or water, although exogenous absorbing species can also be added to the tissue. In the case when water is used as the primary absorbing species, cellular and interstitial water absorbs optical energy and transforms the optical energy into thermal energy. The transport of thermal energy in tissues during treatment is a complex process involving conduction, convection, radiation, metabolism, evaporation and phase change that vary with the functional parameters of the beam of optical energy. It is important in such procedures not to damage tissue underlying or surrounding the target area of tissue. If the functional parameters of the optical energy, such as, for example, wavelength, beam energy density, and/or beam pulse duration, are properly selected, cellular and interstitial water in the patient's skin is heated, causing temperature increases that produce a desired effect. Conversely, improper selection of the functional parameters can result in under-treatment or over-treatment of the tissue. Therefore, it is desirable to accurately control the functional parameter settings used by the treatment device so that the optical energy is delivered to the tissue in a uniform, controlled manner.
Many of the currently marketed medical and/or cosmetic optical energy based devices are used in direct contact with tissue being treated, or can have tissue deposited on them by the treatment process over the course of a treatment. Such devices require cleaning and special care to maintain cleanliness. Such devices can additionally require cleaning to maintain the efficacy of the treatment, as their delivery systems often include a window or some aperture through which the optical energy passes. If these windows or apertures become blocked for example, by foreign substances, scratches, chips, or cracks, then the device typically will not function properly. Conventional devices typically have a monolithic handpiece with unchangeable mechanical, electrical and optical components and connections, which can be difficult to adequately clean and/or sterilize.
A typical method of using conventional monolithic handpieces to deliver an optical energy based treatment is to produce a macroscopic, pulsed treatment beam that is manually moved from one area of the skin to another in a patchwork-like manner or a stamping manner (i.e., the handpiece is not in motion when the treatment beam is applied) in order to treat a larger portion of tissue. Such an approach can have the disadvantage of producing artifacts and sharp boundaries associated with the inaccurate positioning of the individual treatments with respect to the treated skin surface.
More recently, devices are being marketed which employ handpieces which are capable of delivering a treatment as the handpiece is moved across the portion of tissue to be treated. Employing handpieces which can deliver treatment while in motion requires more complex engineering and presents a new set of difficulties for the treatment provider, such as the requirement to maintain one constant treatment speed. More complex handpieces have overcome this limitation by using handpiece speed feedback to automatically adjust functional parameters of the device in order to compensate for handpiece speed and deliver a uniform, controlled treatment.
Increasingly, conventional bulk skin treatment methods are being replaced by fractional treatment methods, as the use of fractional treatment methods has been found to produce fewer and less severe side effects than conventional bulk treatment methods, such as, for example, reduced damage to the epidermal layers of the skin. Fractional treatment methods involve the generation of a large number of treatment zones within a portion of tissue. The optical energy impacts directly on only the relatively small treatment zones, instead of impacting directly on the entire portion of tissue undergoing treatment, as it does in conventional bulk treatments. Thus, a portion of skin treated using a fractional optical energy treatment method is composed of a number of treatment zones where the tissue has been treated directly by the energy, contained within a volume of tissue that has not been treated directly by the energy. The treatment can, for example, produce coagulation and/or necrosis of tissue. Fractional treatment methods make it possible to leave substantial volumes of tissue untreated (e.g., uncoagulated and/or viable) within a portion of tissue that has been treated.
Devices which are capable of providing fractional treatments typically employ a means to scan one or more beams of optical energy across a portion of tissue, or a means to divide one or more beams of optical energy into a plurality of beams, and deliver the plurality of beams to a portion of tissue to be treated. These additional scanning or dividing components are often located in the handpiece, making the handpieces for fractional treatment devices more complex than the handpieces for bulk treatment devices.
Complex handpieces, such as those that deliver uniform, controlled treatments while in motion and/or those which include optical delivery systems that deliver energy in a fractional manner, can require the use of high manufacturing tolerances and/or the use of great precision when connecting the optical components of the handpiece as well as the rest of the device in order for the components of the device to function properly and for the device to deliver the optical energy in an efficient, effective, uniform and controlled manner. For example, a large number of functional parameters need to be properly set in order for an optical energy system and/or source to function properly on its own. Similarly, a large number of functional parameters need to be properly set in order for a handpiece and its optical energy delivery system (e.g., scanner, lens array, or other means for delivering the treatment beam(s) to the portion of tissue) to function properly on their own, as well as to function properly in conjunction with an optical energy system and/or source.
For example, conventional bulk optical energy-based treatments have typically been delivered using a monolithic handpieces containing a few non-moving optical components requiring that only a low level of precision and/or low tolerances be used in making its optical connections in order for a beam of optical energy to pass through it properly, and which do not have any functional parameters which can be adjusted. By comparison, handpieces for fractional delivery devices can contain, for example, precision scanners, lens arrays, and/or rotating wheels, and thus require a high level of coordination in terms of adjustments of functional parameters related to the beam characteristics, the optical path, timing of the beam, timing of moving components, position of moving parts, and/or energy settings between the components of the handpiece and the optical energy system and/or source. Due to the high level of precision required to manufacture and align the optical components, the large number of characteristics which must be determined for the components of the device, and the large number of functional parameters which must be properly set for such devices to function properly, properly adjusting and aligning the components of these devices is not easily done outside the manufacturing setting, and cannot easily be done by a treatment provider. For this reason, the marketed treatment devices employing sophisticated optical energy sources and handpieces have been composed of handpieces and optical energy sources which can only be disconnected and reconnected in a manufacturing setting, and/or by a trained technician outside a manufacturing setting.
Not being able to have the treatment provider easily connect, disconnect, and reconnect the handpieces and/or the optical energy systems and/or sources of these devices limits the utility of the devices, as it can require that a treatment provider purchase a dedicated device for each possible type of treatment, rather than purchasing a device composed of one or more reconnectable handpieces and/or one or more reconnectable optical energy sources which can be combined in different configurations in order to deliver different types of treatments.
The present invention provides devices and methods which address this need by providing reconnectable handpieces, devices comprising reconnectable handpieces and optical energy systems and/or sources, methods of establishing characteristic data of device components, and methods of using the established characteristic data to adjust the components of a device in order for the components to function together properly after being connected. The method of using the established characteristic data to adjust the components of the device uses a controller to access stored characteristic data and make any necessary adjustments to parameter settings, and so can be easily executed by a treatment provider in the location where the device is to be used.